What does picometre mean?
A picometre is a metric unit of length equal to one trillionth of a metre, or 10^-12 metres. It is used when discussing dimensions and distances at the scale of atoms, molecules, biological structures, and engineered nanomaterials. In scientific literature, the unit may be written in full or represented by the symbol pm. Although the number sounds enormous, the unit itself describes an extremely tiny distance: one picometre is one million times smaller than a micrometre and one billion times smaller than a metre. The word is especially associated with nanotechnology, microscopy, molecular biology, and precision engineering. British English normally spells it picometre, while American English uses picometer.
nounA metric unit of length equal to one trillionth of a metre, or 10^-12 metres. It is used in scientific and engineering contexts to measure extremely small distances.
- A metric unit of length equal to 10^-12 metres, used for measuring distances at the scale of atoms, molecules, and nanoscale structures.
"The features were measured on a scale of just a few picometres."
"The microscope resolved features separated by only a few picometres."
"The fabrication process achieved a resolution below one picometre."
The plural is picometres in British spelling and picometers in US spelling.
"Several structural features were measured in picometres."
A picometre is small enough that a single strand of DNA is only a few dozen picometres across.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of picometre
Picometre was formed in the 20th century by combining the metric prefix pico-, denoting 10^-12, with metre, the SI base unit of length. It belongs to a family of metric units formed in the same way, including nanometre, micrometre, centimetre, and kilometre. Its name expresses the scale of measurement directly: a picometre is one trillionth of a metre.
How picometre is actually used
The British spelling is picometre and the US spelling is picometer. The abbreviation pm is conventionally used in scientific writing, although it can sometimes be ambiguous with other units.
Easily confused with picometre
Picometre is the standard British spelling, while picometer is the standard US spelling of the same unit.